btrfs-progs: btrfstune: use on-stack path buffer in change_devices_uuid

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/btrfstune.c b/btrfstune.c
index 0a22b98..e8e3d00 100644 (file)
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -200,28 +200,26 @@ static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
 {
        struct btrfs_root *root = fs_info->chunk_root;
-       struct btrfs_path *path;
+       struct btrfs_path path;
        struct btrfs_key key = {0, 0, 0};
        int ret = 0;
 
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
+       btrfs_init_path(&path);
        /* No transaction again */
-       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
        if (ret < 0)
                goto out;
 
        while (1) {
-               btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+               btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
                if (key.type != BTRFS_DEV_ITEM_KEY ||
                    key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
                        goto next;
-               ret = change_device_uuid(root, path->nodes[0], path->slots[0]);
+               ret = change_device_uuid(root, path.nodes[0], path.slots[0]);
                if (ret < 0)
                        goto out;
 next:
-               ret = btrfs_next_item(root, path);
+               ret = btrfs_next_item(root, &path);
                if (ret < 0)
                        goto out;
                if (ret > 0) {
@@ -230,7 +228,7 @@ next:
                }
        }
 out:
-       btrfs_free_path(path);
+       btrfs_release_path(&path);
        return ret;
 }