[PATCH v2 01/10] erofs-utils: lib: use Z_EROFS_LCLUSTER_TYPE_MAX to simplify switches

[Gao Xiang]

Source kernel commit: 3b7781aeaefb627d4e07c1af9be923f9e8047d8b

Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
 lib/zmap.c | 60 ++++++++++++++++++++++--------------------------------
 1 file changed, 24 insertions(+), 36 deletions(-)

diff --git a/lib/zmap.c b/lib/zmap.c
index 2a9baba..30bb7e3 100644
--- a/lib/zmap.c
+++ b/lib/zmap.c
@@ -282,26 +282,22 @@ static int z_erofs_extent_lookback(struct 
z_erofs_maprecorder *m,
                if (err)
                        return err;
 
-               switch (m->type) {
-               case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
+               if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) {
+                       erofs_err("unknown type %u @ lcn %lu of nid %llu",
+                                 m->type, lcn, vi->nid | 0ULL);
+                       DBG_BUGON(1);
+                       return -EOPNOTSUPP;
+               } else if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
                        lookback_distance = m->delta[0];
                        if (!lookback_distance)
-                               goto err_bogus;
+                               break;
                        continue;
-               case Z_EROFS_LCLUSTER_TYPE_PLAIN:
-               case Z_EROFS_LCLUSTER_TYPE_HEAD1:
-               case Z_EROFS_LCLUSTER_TYPE_HEAD2:
+               } else {
                        m->headtype = m->type;
                        m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
                        return 0;
-               default:
-                       erofs_err("unknown type %u @ lcn %lu of nid %llu",
-                                 m->type, lcn, vi->nid | 0ULL);
-                       DBG_BUGON(1);
-                       return -EOPNOTSUPP;
                }
        }
-err_bogus:
        erofs_err("bogus lookback distance %u @ lcn %lu of nid %llu",
                  lookback_distance, m->lcn | 0ULL, vi->nid);
        DBG_BUGON(1);
@@ -345,36 +341,30 @@ static int z_erofs_get_extent_compressedlen(struct 
z_erofs_maprecorder *m,
        DBG_BUGON(lcn == initial_lcn &&
                  m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);
 
-       switch (m->type) {
-       case Z_EROFS_LCLUSTER_TYPE_PLAIN:
-       case Z_EROFS_LCLUSTER_TYPE_HEAD1:
-       case Z_EROFS_LCLUSTER_TYPE_HEAD2:
+       if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
+               if (m->delta[0] != 1) {
+                       erofs_err("bogus CBLKCNT @ lcn %lu of nid %llu",
+                                 lcn, vi->nid | 0ULL);
+                       DBG_BUGON(1);
+                       return -EFSCORRUPTED;
+               }
+               if (m->compressedblks)
+                       goto out;
+       } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) {
                /*
                 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
                 * rather than CBLKCNT, it's a 1 block-sized pcluster.
                 */
                m->compressedblks = 1;
-               break;
-       case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
-               if (m->delta[0] != 1)
-                       goto err_bonus_cblkcnt;
-               if (m->compressedblks)
-                       break;
-               /* fallthrough */
-       default:
-               erofs_err("cannot found CBLKCNT @ lcn %lu of nid %llu",
-                         lcn, vi->nid | 0ULL);
-               DBG_BUGON(1);
-               return -EFSCORRUPTED;
+               goto out;
        }
-out:
-       m->map->m_plen = erofs_pos(sbi, m->compressedblks);
-       return 0;
-err_bonus_cblkcnt:
-       erofs_err("bogus CBLKCNT @ lcn %lu of nid %llu",
+       erofs_err("cannot found CBLKCNT @ lcn %lu of nid %llu",
                  lcn, vi->nid | 0ULL);
        DBG_BUGON(1);
        return -EFSCORRUPTED;
+out:
+       m->map->m_plen = erofs_pos(sbi, m->compressedblks);
+       return 0;
 }
 
 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
@@ -402,9 +392,7 @@ static int z_erofs_get_extent_decompressedlen(struct 
z_erofs_maprecorder *m)
                                m->delta[1] = 1;
                                DBG_BUGON(1);
                        }
-               } else if (m->type == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
-                          m->type == Z_EROFS_LCLUSTER_TYPE_HEAD1 ||
-                          m->type == Z_EROFS_LCLUSTER_TYPE_HEAD2) {
+               } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) {
                        if (lcn != headlcn)
                                break;  /* ends at the next HEAD lcluster */
                        m->delta[1] = 1;
-- 
2.43.5