btrfs-progs: check: use on-stack path buffer in check_fs_root_v2

We don't need to conserve stack space too much unlike kernel, also
remove one error condition.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-check.c b/cmds-check.c
index 4cd0fcd..fd6bbd2 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -4972,7 +4972,7 @@ out:
  */
 static int check_fs_root_v2(struct btrfs_root *root, unsigned int ext_ref)
 {
-       struct btrfs_path *path;
+       struct btrfs_path path;
        struct node_refs nrefs;
        struct btrfs_root_item *root_item = &root->root_item;
        int ret, wret;
@@ -4988,38 +4988,35 @@ static int check_fs_root_v2(struct btrfs_root *root, unsigned int ext_ref)
        if (ret < 0)
                return ret;
 
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-
        memset(&nrefs, 0, sizeof(nrefs));
        level = btrfs_header_level(root->node);
+       btrfs_init_path(&path);
 
        if (btrfs_root_refs(root_item) > 0 ||
            btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
-               path->nodes[level] = root->node;
-               path->slots[level] = 0;
+               path.nodes[level] = root->node;
+               path.slots[level] = 0;
                extent_buffer_get(root->node);
        } else {
                struct btrfs_key key;
 
                btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
                level = root_item->drop_level;
-               path->lowest_level = level;
-               ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+               path.lowest_level = level;
+               ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
                if (ret < 0)
                        goto out;
                ret = 0;
        }
 
        while (1) {
-               wret = walk_down_tree_v2(root, path, &level, &nrefs, ext_ref);
+               wret = walk_down_tree_v2(root, &path, &level, &nrefs, ext_ref);
                if (wret < 0)
                        ret = wret;
                if (wret != 0)
                        break;
 
-               wret = walk_up_tree_v2(root, path, &level);
+               wret = walk_up_tree_v2(root, &path, &level);
                if (wret < 0)
                        ret = wret;
                if (wret != 0)
@@ -5027,7 +5024,7 @@ static int check_fs_root_v2(struct btrfs_root *root, unsigned int ext_ref)
        }
 
 out:
-       btrfs_free_path(path);
+       btrfs_release_path(&path);
        return ret;
 }