erofs: clean up z_erofs_collector_begin()

Rearrange the code and get rid of all gotos.

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220715154203.48093-3-hsiangkao@linux.alibaba.com

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 1b6816d..c7be447 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -521,7 +521,7 @@ err_out:
 static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe)
 {
        struct erofs_map_blocks *map = &fe->map;
-       struct erofs_workgroup *grp;
+       struct erofs_workgroup *grp = NULL;
        int ret;
 
        DBG_BUGON(fe->pcl);
@@ -530,33 +530,31 @@ static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe)
        DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_NIL);
        DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
 
-       if (map->m_flags & EROFS_MAP_META) {
-               if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) {
-                       DBG_BUGON(1);
-                       return -EFSCORRUPTED;
-               }
-               goto tailpacking;
+       if (!(map->m_flags & EROFS_MAP_META)) {
+               grp = erofs_find_workgroup(fe->inode->i_sb,
+                                          map->m_pa >> PAGE_SHIFT);
+       } else if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) {
+               DBG_BUGON(1);
+               return -EFSCORRUPTED;
        }
 
-       grp = erofs_find_workgroup(fe->inode->i_sb, map->m_pa >> PAGE_SHIFT);
        if (grp) {
                fe->pcl = container_of(grp, struct z_erofs_pcluster, obj);
+               ret = -EEXIST;
        } else {
-tailpacking:
                ret = z_erofs_register_pcluster(fe);
-               if (!ret)
-                       goto out;
-               if (ret != -EEXIST)
-                       return ret;
        }
 
-       ret = z_erofs_lookup_pcluster(fe);
-       if (ret) {
-               erofs_workgroup_put(&fe->pcl->obj);
+       if (ret == -EEXIST) {
+               ret = z_erofs_lookup_pcluster(fe);
+               if (ret) {
+                       erofs_workgroup_put(&fe->pcl->obj);
+                       return ret;
+               }
+       } else if (ret) {
                return ret;
        }
 
-out:
        z_erofs_pagevec_ctor_init(&fe->vector, Z_EROFS_NR_INLINE_PAGEVECS,
                                  fe->pcl->pagevec, fe->pcl->vcnt);
        /* since file-backed online pages are traversed in reverse order */