Re: [PATCH 10/14] btrfs: use btrfs_read_node_slot in btrfs_qgroup_trace_subtree

[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/qgroup.c | 15 +++------------
>  1 file changed, 3 insertions(+), 12 deletions(-)
>
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 8d112ff7b5ae..25e3b7105e8a 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -2182,30 +2182,21 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
>         level = root_level;
>         while (level >= 0) {
>                 if (path->nodes[level] == NULL) {
> -                       struct btrfs_key first_key;
>                         int parent_slot;
> -                       u64 child_gen;
>                         u64 child_bytenr;
>
>                         /*
> -                        * We need to get child blockptr/gen from parent before
> -                        * we can read it.
> +                        * We need to get child blockptr from parent before we
> +                        * can read it.
>                           */
>                         eb = path->nodes[level + 1];
>                         parent_slot = path->slots[level + 1];
>                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
> -                       child_gen = btrfs_node_ptr_generation(eb, parent_slot);
> -                       btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
>
> -                       eb = read_tree_block(fs_info, child_bytenr, child_gen,
> -                                            level, &first_key);
> +                       eb = btrfs_read_node_slot(eb, parent_slot);
>                         if (IS_ERR(eb)) {
>                                 ret = PTR_ERR(eb);
>                                 goto out;
> -                       } else if (!extent_buffer_uptodate(eb)) {
> -                               free_extent_buffer(eb);
> -                               ret = -EIO;
> -                               goto out;
>                         }
>
>                         path->nodes[level] = eb;
> --
> 2.26.2
>


-- 
Filipe David Manana,

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