Re: [PATCH 1/3] btrfs: run delayed iputs before committing

[Nikolay Borisov <nborisov@suse.com>]

On 3.12.18 г. 18:06 ч., Josef Bacik wrote:
> Delayed iputs means we can have final iputs of deleted inodes in the
> queue, which could potentially generate a lot of pinned space that could
> be free'd.  So before we decide to commit the transaction for ENOPSC
> reasons, run the delayed iputs so that any potential space is free'd up.
> If there is and we freed enough we can then commit the transaction and
> potentially be able to make our reservation.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Reviewed-by: Omar Sandoval <osandov@fb.com>

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

> ---
>  fs/btrfs/extent-tree.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 8dfddfd3f315..0127d272cd2a 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4953,6 +4953,15 @@ static void flush_space(struct btrfs_fs_info *fs_info,
>  			ret = 0;
>  		break;
>  	case COMMIT_TRANS:
> +		/*
> +		 * If we have pending delayed iputs then we could free up a
> +		 * bunch of pinned space, so make sure we run the iputs before
> +		 * we do our pinned bytes check below.
> +		 */
> +		mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
> +		btrfs_run_delayed_iputs(fs_info);
> +		mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
> +
>  		ret = may_commit_transaction(fs_info, space_info);
>  		break;
>  	default:
>