[PATCH v2 2/2] erofs: get rid of kaddr in `struct z_erofs_maprecorder`

From: Gao Xiang
Date: Thu Oct 10 2024 - 19:59:01 EST


`kaddr` becomes useless after switching to metabuf.

Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
---
change since v1:
- shouldn't move `m->lcn` downwards since `lcn` has been changed.

fs/erofs/zmap.c | 32 ++++++++++++--------------------
1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index e980e29873a5..37516d7ea811 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -10,8 +10,6 @@
struct z_erofs_maprecorder {
struct inode *inode;
struct erofs_map_blocks *map;
- void *kaddr;
-
unsigned long lcn;
/* compression extent information gathered */
u8 type, headtype;
@@ -33,14 +31,11 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
struct z_erofs_lcluster_index *di;
unsigned int advise;

- m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
- pos, EROFS_KMAP);
- if (IS_ERR(m->kaddr))
- return PTR_ERR(m->kaddr);
-
- m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
+ di = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, EROFS_KMAP);
+ if (IS_ERR(di))
+ return PTR_ERR(di);
m->lcn = lcn;
- di = m->kaddr;
+ m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);

advise = le16_to_cpu(di->di_advise);
m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK;
@@ -53,8 +48,7 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
DBG_BUGON(1);
return -EFSCORRUPTED;
}
- m->compressedblks = m->delta[0] &
- ~Z_EROFS_LI_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]);
@@ -110,9 +104,9 @@ 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, lo, lobits, encodebits, nblk, bytes;
- int i;
- u8 *in, type;
bool big_pcluster;
+ u8 *in, type;
+ int i;

if (1 << amortizedshift == 4 && lclusterbits <= 14)
vcnt = 2;
@@ -121,6 +115,10 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
else
return -EOPNOTSUPP;

+ in = erofs_read_metabuf(&m->map->buf, m->inode->i_sb, pos, EROFS_KMAP);
+ if (IS_ERR(in))
+ return PTR_ERR(in);
+
/* it doesn't equal to round_up(..) */
m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
(vcnt << amortizedshift);
@@ -128,9 +126,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
bytes = pos & ((vcnt << amortizedshift) - 1);
-
- in = m->kaddr - bytes;
-
+ in -= bytes;
i = bytes >> amortizedshift;

lo = decode_compactedbits(lobits, in, encodebits * i, &type);
@@ -255,10 +251,6 @@ static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
amortizedshift = 2;
out:
pos += lcn * (1 << amortizedshift);
- m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
- pos, EROFS_KMAP);
- if (IS_ERR(m->kaddr))
- return PTR_ERR(m->kaddr);
return unpack_compacted_index(m, amortizedshift, pos, lookahead);
}

--
2.43.5