Re: [PATCH 5/8] btrfs: refactor the ticket wakeup code

[Nikolay Borisov <nborisov@suse.com>]

On 16.08.19 г. 17:19 ч., Josef Bacik wrote:
> Now that btrfs_space_info_add_old_bytes simply checks if we can make the
> reservation and updates bytes_may_use, there's no reason to have both
> helpers in place.  Factor out the ticket wakeup logic into it's own
> helper, make btrfs_space_info_add_old_bytes() update bytes_may_use and
> then call the wakeup helper, and replace all calls to
> btrfs_space_info_add_new_bytes() with the wakeup helper.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Generally looks good and much nicer than before, one small nit below,
when fixed you can add:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/extent-tree.c |  4 ++--
>  fs/btrfs/space-info.c  | 53 +++---------------------------------------
>  fs/btrfs/space-info.h  | 19 ++++++++++-----
>  3 files changed, 18 insertions(+), 58 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 32f9473c8426..08c6fcfc418d 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -2863,8 +2863,8 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
>  			spin_unlock(&global_rsv->lock);
>  			/* Add to any tickets we may have */
>  			if (len)
> -				btrfs_space_info_add_new_bytes(fs_info,
> -						space_info, len);
> +				btrfs_try_to_wakeup_tickets(fs_info,
> +							    space_info);
>  		}
>  		spin_unlock(&space_info->lock);
>  	}
> diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
> index 5f123b36fdcd..8a1c7ada67cb 100644
> --- a/fs/btrfs/space-info.c
> +++ b/fs/btrfs/space-info.c
> @@ -131,9 +131,7 @@ void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
>  	found->bytes_readonly += bytes_readonly;
>  	if (total_bytes > 0)
>  		found->full = 0;
> -	btrfs_space_info_add_new_bytes(info, found,
> -				       total_bytes - bytes_used -
> -				       bytes_readonly);
> +	btrfs_try_to_wakeup_tickets(info, found);
>  	spin_unlock(&found->lock);
>  	*space_info = found;
>  }
> @@ -229,17 +227,13 @@ static int can_overcommit(struct btrfs_fs_info *fs_info,
>   * This is for space we already have accounted in space_info->bytes_may_use, so
>   * basically when we're returning space from block_rsv's.
>   */
> -void btrfs_space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
> -				    struct btrfs_space_info *space_info,
> -				    u64 num_bytes)
> +void btrfs_try_to_wakeup_tickets(struct btrfs_fs_info *fs_info,
> +				 struct btrfs_space_info *space_info)
>  {
>  	struct list_head *head;
>  	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
>  
> -	spin_lock(&space_info->lock);


Add an lockdep_assert_held(&space_info->lock);

<snip>