superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

erofs: consolidate z_erofs_extent_lookback() 

The initial m.delta[0] also needs to be checked against zero.

In addition, also drop the redundant logic that errors out for
lcn == 0 / m.delta[0] == 1 case.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
pull/1354/merge
Gao Xiang 2025-10-17 15:05:39 +08:00
parent e13d315ae0
commit 2a13fc417f
1 changed files with 6 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
fs/erofs/zmap.c
View File

@ -272,20 +272,19 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
unsigned long lcn = m->lcn - lookback_distance; unsigned long lcn = m->lcn - lookback_distance;
int err; int err;
if (!lookback_distance)
break;
err = z_erofs_load_lcluster_from_disk(m, lcn, false); err = z_erofs_load_lcluster_from_disk(m, lcn, false);
if (err) if (err)
return err; return err;
if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
lookback_distance = m->delta[0]; lookback_distance = m->delta[0];
if (!lookback_distance)
break;
continue; continue;
} else {
m->headtype = m->type;
m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
return 0;
} }
m->headtype = m->type;
m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
return 0;
} }
erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu", erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu",
lookback_distance, m->lcn, vi->nid); lookback_distance, m->lcn, vi->nid);
@ -435,13 +434,6 @@ static int z_erofs_map_blocks_fo(struct inode *inode,
end = inode->i_size; end = inode->i_size;
} else { } else {
if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) { if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
/* m.lcn should be >= 1 if endoff < m.clusterofs */
if (!m.lcn) {
erofs_err(sb, "invalid logical cluster 0 at nid %llu",
vi->nid);
err = -EFSCORRUPTED;
goto unmap_out;
}
end = (m.lcn << lclusterbits) | m.clusterofs; end = (m.lcn << lclusterbits) | m.clusterofs;
map->m_flags |= EROFS_MAP_FULL_MAPPED; map->m_flags |= EROFS_MAP_FULL_MAPPED;
m.delta[0] = 1; m.delta[0] = 1;