[PATCH] erofs: clean up zmap.c

From: Gao Xiang
Date: Thu Jun 15 2023 - 02:32:40 EST


Several trivial cleanups which aren't quite necessary to split:

- Rename lcluster load functions as well as justify full indexes
since they are typically used for global deduplication for
compressed data;

- Avoid unnecessary lines, comments for simplicity.

No logic changes.

Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
---
fs/erofs/zmap.c | 69 +++++++++++++++++++++----------------------------
1 file changed, 29 insertions(+), 40 deletions(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 920fb4dbc731..47f5a87be7b1 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -22,8 +22,8 @@ struct z_erofs_maprecorder {
bool partialref;
};

-static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
- unsigned long lcn)
+static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
+ unsigned long lcn)
{
struct inode *const inode = m->inode;
struct erofs_inode *const vi = EROFS_I(inode);
@@ -226,8 +226,8 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
return 0;
}

-static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
- unsigned long lcn, bool lookahead)
+static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
+ unsigned long lcn, bool lookahead)
{
struct inode *const inode = m->inode;
struct erofs_inode *const vi = EROFS_I(inode);
@@ -277,23 +277,23 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
return unpack_compacted_index(m, amortizedshift, pos, lookahead);
}

-static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
- unsigned int lcn, bool lookahead)
+static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned int lcn, bool lookahead)
{
- const unsigned int datamode = EROFS_I(m->inode)->datalayout;
-
- if (datamode == EROFS_INODE_COMPRESSED_FULL)
- return legacy_load_cluster_from_disk(m, lcn);
-
- if (datamode == EROFS_INODE_COMPRESSED_COMPACT)
- return compacted_load_cluster_from_disk(m, lcn, lookahead);
-
- return -EINVAL;
+ switch (EROFS_I(m->inode)->datalayout) {
+ case EROFS_INODE_COMPRESSED_FULL:
+ return z_erofs_load_full_lcluster(m, lcn);
+ case EROFS_INODE_COMPRESSED_COMPACT:
+ return z_erofs_load_compact_lcluster(m, lcn, lookahead);
+ default:
+ return -EINVAL;
+ }
}

static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
unsigned int lookback_distance)
{
+ struct super_block *sb = m->inode->i_sb;
struct erofs_inode *const vi = EROFS_I(m->inode);
const unsigned int lclusterbits = vi->z_logical_clusterbits;

@@ -301,21 +301,15 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
unsigned long lcn = m->lcn - lookback_distance;
int err;

- /* load extent head logical cluster if needed */
- err = z_erofs_load_cluster_from_disk(m, lcn, false);
+ err = z_erofs_load_lcluster_from_disk(m, lcn, false);
if (err)
return err;

switch (m->type) {
case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
- if (!m->delta[0]) {
- erofs_err(m->inode->i_sb,
- "invalid lookback distance 0 @ nid %llu",
- vi->nid);
- DBG_BUGON(1);
- return -EFSCORRUPTED;
- }
lookback_distance = m->delta[0];
+ if (!lookback_distance)
+ goto err_bogus;
continue;
case Z_EROFS_LCLUSTER_TYPE_PLAIN:
case Z_EROFS_LCLUSTER_TYPE_HEAD1:
@@ -324,16 +318,15 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
return 0;
default:
- erofs_err(m->inode->i_sb,
- "unknown type %u @ lcn %lu of nid %llu",
+ erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu",
m->type, lcn, vi->nid);
DBG_BUGON(1);
return -EOPNOTSUPP;
}
}
-
- erofs_err(m->inode->i_sb, "bogus lookback distance @ nid %llu",
- vi->nid);
+err_bogus:
+ erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu",
+ lookback_distance, lcn, vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
@@ -365,7 +358,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
if (m->compressedblks)
goto out;

- err = z_erofs_load_cluster_from_disk(m, lcn, false);
+ err = z_erofs_load_lcluster_from_disk(m, lcn, false);
if (err)
return err;

@@ -397,9 +390,8 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
break;
fallthrough;
default:
- erofs_err(m->inode->i_sb,
- "cannot found CBLKCNT @ lcn %lu of nid %llu",
- lcn, vi->nid);
+ erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn,
+ vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
@@ -407,9 +399,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
map->m_plen = erofs_pos(sb, m->compressedblks);
return 0;
err_bonus_cblkcnt:
- erofs_err(m->inode->i_sb,
- "bogus CBLKCNT @ lcn %lu of nid %llu",
- lcn, vi->nid);
+ erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
@@ -430,7 +420,7 @@ static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
return 0;
}

- err = z_erofs_load_cluster_from_disk(m, lcn, true);
+ err = z_erofs_load_lcluster_from_disk(m, lcn, true);
if (err)
return err;

@@ -477,7 +467,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
initial_lcn = ofs >> lclusterbits;
endoff = ofs & ((1 << lclusterbits) - 1);

- err = z_erofs_load_cluster_from_disk(&m, initial_lcn, false);
+ err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false);
if (err)
goto unmap_out;

@@ -535,8 +525,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
vi->z_tailextent_headlcn = m.lcn;
/* for non-compact indexes, fragmentoff is 64 bits */
- if (fragment &&
- vi->datalayout == EROFS_INODE_COMPRESSED_FULL)
+ if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL)
vi->z_fragmentoff |= (u64)m.pblk << 32;
}
if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
--
2.24.4