Re: [PATCH 07/14] btrfs: use btrfs_read_node_slot in walk_down_tree

[Filipe Manana <fdmanana@gmail.com>]

On Thu, Nov 5, 2020 at 3:47 PM Josef Bacik <josef@toxicpanda.com> wrote:
>
> We're open-coding btrfs_read_node_slot() here, replace with the helper.
>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Reviewed-by: Filipe Manana <fdmanana@suse.com>

I couldn't get anymore the lockdep splat I reported before (after
applying the whole patchset of course), it used to happen very often
with btrfs/033.

Looks good, thanks.

> ---
>  fs/btrfs/ref-verify.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
>
> diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
> index 488bc3dd3c2b..4b9b6c52a83b 100644
> --- a/fs/btrfs/ref-verify.c
> +++ b/fs/btrfs/ref-verify.c
> @@ -551,29 +551,15 @@ static int process_leaf(struct btrfs_root *root,
>  static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,
>                           int level, u64 *bytenr, u64 *num_bytes)
>  {
> -       struct btrfs_fs_info *fs_info = root->fs_info;
>         struct extent_buffer *eb;
> -       u64 block_bytenr, gen;
>         int ret = 0;
>
>         while (level >= 0) {
>                 if (level) {
> -                       struct btrfs_key first_key;
> -
> -                       block_bytenr = btrfs_node_blockptr(path->nodes[level],
> -                                                          path->slots[level]);
> -                       gen = btrfs_node_ptr_generation(path->nodes[level],
> -                                                       path->slots[level]);
> -                       btrfs_node_key_to_cpu(path->nodes[level], &first_key,
> -                                             path->slots[level]);
> -                       eb = read_tree_block(fs_info, block_bytenr, gen,
> -                                            level - 1, &first_key);
> +                       eb = btrfs_read_node_slot(path->nodes[level],
> +                                                 path->slots[level]);
>                         if (IS_ERR(eb))
>                                 return PTR_ERR(eb);
> -                       if (!extent_buffer_uptodate(eb)) {
> -                               free_extent_buffer(eb);
> -                               return -EIO;
> -                       }
>                         btrfs_tree_read_lock(eb);
>                         path->nodes[level-1] = eb;
>                         path->slots[level-1] = 0;
> --
> 2.26.2
>


-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”